Mbms data transmission and receiving in packet based on mobile communication system

Abstract

Provided is a data transmission/reception method for simultaneously transmitting MBMS data from multiple cells through a HARQ method by allocating a shared feedback channel to user equipments of each cell and, when there is an error in the transmitted MBMS data, reporting feedback on a cell basis. The method for transmitting identical MBMS data from multiple cells to user equipments includes: a) transmitting control information including information on a service group identifier for the MBMS data and on a cell-specific shared feedback channel shared by user equipments of a cell to the user equipments through a control channel; b) transmitting MBMS data to the user equipments; c) when an acknowledgement is received through the shared feedback channel from at least one user equipment, transmitting radio resource information of retransmission data to the user equipments through a downlink control channel; and d) transmitting the retransmission data to the user equipments.

1 . A method for transmitting identical Multimedia Broadcast Multicast Service (MBMS) data from multiple cells to user equipments in a packet-based mobile communication system, comprising:
 transmitting control information including information on a service group identifier for the MBMS data and on a cell-specific shared feedback channel shared by user equipments of a cell to the user equipments through a control channel;   transmitting MBMS data packets to the user equipments;   when an acknowledgement is received through the shared feedback channel from at least any one user equipment, transmitting radio resource information of retransmission data to the user equipments through a downlink control channel; and   transmitting the retransmission data to the user equipments.   
     
     
         2 . The method of  claim 1 , wherein the retransmission data are transmitted using unicast resources in the transmitting the retransmission data. 
     
     
         3 . The method of  claim 1 , wherein the control information includes time information indicating when transmission through the downlink control channel is available in the transmitting control information. 
     
     
         4 . The method of  claim 3 , wherein the shared feedback channel information and the time information indicating when transmission through the downlink control channel is available are periodically transmitted to the user equipments. 
     
     
         5 . The method of  claim 3 , wherein the shared feedback channel is managed by a base station of each cell, and different time and subcarriers are allocated to each base station. 
     
     
         6 . The method of  claim 3 , wherein time and frequency positions of the shared feedback channel are allocated differently according to whether a user equipment maintains uplink sync. 
     
     
         7 . The method of  claim 6 , wherein a shared feedback channel for a user equipment maintaining uplink sync is allocated temporally prior to a user equipment not maintaining uplink sync. 
     
     
         8 . The method of  claim 7 , wherein the user equipment maintaining uplink sync uses an uplink control as the shared feedback channel, and the user equipment not maintaining uplink sync uses a random access channel as the shared feedback channel. 
     
     
         9 . A method for transmitting identical Multimedia Broadcast Multicast Service (MBMS) data from multiple cells to user equipments in a packet-based mobile communication system and receiving the MBMS data in the user equipments, comprising:
 receiving control information including information on a service group identifier for the MBMS data and on a cell-specific shared feedback channel shared by user equipments of a cell from a base station through a control channel;)   receiving MBMS data packets;   transmitting a Cyclic Redundancy Check (CRC) result obtained by executing CRC onto the received MBMS data through the shared feedback channel;   receiving radio resource position information of retransmission data through a downlink control channel; and   receiving the retransmission data.   
     
     
         10 . The method of  claim 9 , wherein the retransmission data are received using unicast resources in the receiving the retransmission data. 
     
     
         11 . The method of  claim 9 , wherein the control information includes time information indicating when transmission through the downlink control channel is available in the receiving control information. 
     
     
         12 . The method of  claim 11 , wherein the shared feedback channel information and the time information indicating when transmission through the downlink control channel is available are periodically received. 
     
     
         13 . The method of  claim 11 , wherein the shared feedback channel is managed by a base station of each cell, and different time and subcarriers are allocated to each base station. 
     
     
         14 . The method of  claim 11 , wherein time and frequency positions of the shared feedback channel are allocated differently according to whether a user equipment maintains uplink sync. 
     
     
         15 . The method of  claim 14 , wherein in the transmitting a Cyclic Redundancy Check (CRC) result, only when an error is detected in the received packets after the CRC, an acknowledgement is transmitted through the shared feedback channel. 
     
     
         16 . The method of  claim 14 , wherein in the receiving radio resource position information of retransmission data, when data received through the downlink control channel are decoded in a state that no acknowledgement is transmitted through the shared feedback channel and the decoded data includes radio resource position related to the retransmission data, no acknowledgement is transmitted through the shared feedback channel.